What is the evidence that global warming activists use to advance the idea that humans are causing global warming?

The confirmation that man-made CO2 is causing a global warming resembles the chain of proof in a court case. CO2 keeps the Earth hotter than it would be without it. People are adding CO2 to the environment, for the most part by consuming non-renewable energy sources. What's more, there is observational proof that the rising temperatures are being caused by the expanded CO2.